Skip to main content

Linux Command List

Count folder's size​

du -sch /path/to/folder/*type

Set Time & Date NTP​

sudo timedatectl set-ntp yes

Set default shell​

sudo ln -fs /bin/bash /bin/sh

Make zstdmt as zstd​

zstdmt is faster than zstd, since it uses multi-threading.

sudo ln -s /usr/bin/zstdmt /usr/bin/zstd

Add user & group​

sudo adduser [username]

P.S. Don't use useradd to add user, it will not create home directory for user.

Add user to sudo group​

sudo usermod -aG sudo [username]

Change user password

sudo passwd [username]

Delete user​

sudo userdel -r -f [username]

Delete group​

sudo groupdel -f [groupname]

Change default editor to vim​

sudo update-alternatives --config editor

And then choose vim.basic:

There are 3 choices for the alternative editor (providing /usr/bin/editor).

  Selection    Path                Priority   Status
------------------------------------------------------------
* 0            /bin/nano            40        auto mode
  1            /bin/nano            40        manual mode
  2            /usr/bin/vim.basic   30        manual mode
  3            /usr/bin/vim.tiny    15        manual mode

Press <enter> to keep the current choice[*], or type selection number: 2
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/editor (editor) in manual mode

Use tee instead of echo to add lines into file​

The redirection is done by the shell before sudo is even started.
So either make sure the redirection happens in a shell with the right permissions

sudo bash -c 'echo "hello" > f.txt'

Or use tee

echo "hello" | sudo tee f.txt  # add -a for append (>>)

Scan WiFi​

sudo iwlist wlan0 scan

Search Depend packages of Application​

Way 1​

apt-cache depends build-essential

Way 2​

apt-cache showpkg build-essential

APT Error Fix​

If it shows

E: Encountered a section with no Package: header

Just clean the error link

sudo rm /var/lib/apt/lists/* -vf

And then

sudo apt-get update

Start SSH​

sudo /etc/init.d/ssh start

Change SSH Port​

sudo vim /etc/ssh/sshd_config

then

sudo service ssh restart

Regenerate SSH Key​

ssh-keygen -R "you server hostname or ip"

Set default path of terminal​

echo 'cd ~/Desktop/' >> ~/.bashrc

If in MacOS, use

echo 'cd ~/Desktop/' >> ~/.zprofile

Clear history​

history -c

If in MacOS, and you're using zsh as default shell, use

history -p

Zip​

zip

  • -h Show the help interface
  • -m After the file is compressed, delete the original file
  • -o Set the latest change time of all files in the archive to the time of compression
  • -q Quiet mode, does not display the execution of instructions during compression
  • -r Treats all subdirectories under the specified directory together with the file
  • -P Set the compression password

Examples​

Create one archive containing multiple folders and files:

zip -r backup.zip documents photos report.pdf

Create one archive for each folder:

for folder in project-a project-b; do
  zip -r "${folder}.zip" "$folder"
done

Create one archive for each file that matches a pattern:

for file in *.log; do
  zip "${file%.log}.zip" "$file"
done

Unzip​

unzip

  • -l Show the files whitch contained in the compressed file
  • -t Check if the compressed file is correct
  • -P<password> Unzip files with password

Example​

Extract an archive into a specific directory:

unzip backup.zip -d restored-files

Terminal​

  • Ctrl + Alt + F2 = Terminal
  • Alt + F7 = Exit Terminal

Rclone​

Show process every 1 second when upload files:

rclone copy -v --stats 1s [File] [Target]

Remove rclone:

sudo rm /usr/bin/rclone
sudo rm /usr/local/share/man/man1/rclone.1

Rclone Config File

rclone -h | grep "Config file"

Screen​

Kill specific screen

screen -S [pid/name] -X quit

Or

kill [pid]

Kill all screen

killall screen